BLM31KN271SN1L Ferrite Bead Specifications and Applications

ElecSuppliers Part Number GuideSep 26, 2026

BLM31KN271SN1L is a chip ferrite bead from Murata designed for noise suppression in electronic circuits. It belongs to the BLM31KN series and uses a 3216 metric size, also commonly identified as 1206 inch size.

The ferrite bead is designed to suppress high-frequency noise on power and signal lines while maintaining a low DC resistance. It can be used in consumer electronics, industrial equipment, communication equipment, power equipment, and other PCB-based electronic systems.

BLM31KN271SN1L Key Specifications

BLM31KN271SN1L has a typical impedance of 270 ohms at 100 MHz with a tolerance of ±25%. Its maximum initial DC resistance is 0.016 ohms.

The rated current is 4.5 A at an ambient temperature of 85°C and 3.0 A at 125°C. The operating temperature range is -55°C to +125°C.

The component uses a single circuit and is supplied in a surface-mount configuration suitable for automated PCB assembly.

BLM31KN271SN1L Package and Construction

BLM31KN271SN1L uses the 3216 size code, corresponding to approximately 3.2 mm × 1.6 mm in the 1206 inch package designation. Its compact SMD structure allows it to be installed directly on the PCB using standard surface-mount manufacturing processes.

The physical dimensions and land pattern should be checked against the latest Murata product documentation when creating a production PCB footprint.

BLM31KN271SN1L Electrical Characteristics

The 270-ohm impedance rating is specified at 100 MHz, making the component suitable for reducing high-frequency interference on electronic power and signal lines.

DC resistance is an important parameter when selecting a ferrite bead for a power line. With a maximum initial DC resistance of 0.016 ohms, BLM31KN271SN1L is designed to provide noise suppression while limiting the DC voltage drop and power loss introduced by the bead.

Rated current should also be evaluated together with operating temperature. The allowable current decreases as the ambient temperature increases, so thermal conditions need to be considered in high-current applications.

BLM31KN271SN1L Applications

BLM31KN271SN1L can be used for EMI and noise suppression in a variety of electronic products. Typical applications include power supply lines, communication equipment, industrial control systems, consumer electronics, information equipment, and other digital electronic devices.

It can be placed near a power input, IC supply line, interface circuit, or other noise-sensitive section of a PCB to help reduce unwanted high-frequency noise.

The appropriate ferrite bead depends on the frequency range and noise characteristics of the target circuit, so impedance alone should not be used as the only selection criterion.

BLM31KN271SN1L Design Considerations

When selecting BLM31KN271SN1L, engineers should consider impedance, DC resistance, rated current, operating temperature, and the frequency range of the interference.

The 270-ohm specification applies at 100 MHz and does not represent a constant impedance across all frequencies. Actual suppression performance depends on the impedance-frequency characteristics of the ferrite bead and the surrounding circuit.

For power applications, the DC resistance and current rating are particularly important. For signal applications, engineers should also consider the possible effect of the ferrite bead on the desired signal.

BLM31KN271SN1L Compared With Other BLM31KN Versions

The BLM31KN family includes multiple impedance values while maintaining the same general 3216 or 1206 package format. For example, related versions are available with impedance ratings such as 120 ohms, 470 ohms, 600 ohms, 800 ohms, and 1000 ohms at 100 MHz.

Higher impedance does not automatically mean that a particular ferrite bead is more suitable for an application. The required impedance, current capability, DC resistance, and frequency characteristics should be evaluated based on the actual circuit.

BLM31KN271SN1L Sourcing Considerations

When sourcing BLM31KN271SN1L, buyers should specify the complete Murata part number because similar BLM31KN products can have different impedance ratings, packaging codes, or application classifications.

For production procurement, it is important to verify the exact package, impedance value, rated current, DC resistance, operating temperature range, and packaging method. Buyers should also confirm current manufacturer availability and production status before placing large-volume orders.

For PCB replacement projects, the original part number should be compared with the proposed alternative to ensure that electrical characteristics and physical dimensions are compatible.